Scissors



July 14, 1931. M. PARKER scrssons Filed March 7 1927 2 Sheets-Sheet 1 A;ATTORNEYS July 14, 1931. M. PARKER 1,814,959

SCISSORS Filed March 7, 1927 2 Sheets-Sheet 2 A; ATIORNEYJ Patented July14, 1931 PATENT {OFFICE MORGAN PARKER, OF NEW YORK, N. Y.

SGISSORS Application filed March 7, 1927. Serial No. 173,528.

This invention relates to scissors having replaceable blades or cuttingedges. Scissors and shears which are in constant use must be continuallyresharpened. This is not only expensive and time-consuming, especiallyif the blades are ground to a properly serrated cutting edge,,as forbarbers shears, but after a time the grinding wears the blades to such acondition that the scissors must be dis- 1o carded. In some instancestoo it may be difficult to secure the services of a skillful grinder, sothat the scissors must either be poorly ground or be used when too dullfor efficient cutting. Furthermore, the blades of the common type ofscissors should be made of high grade cutlery steel throughout if theyare to present and retain a keen cutting edge after each grinding.

. volves drop-forging difliculties.

0 It was early recognized that a two-part blade would solve some ofthese difliculties. A tool steel cutting blade welded or mechanicallyattached to a softer metal shank simpli- .fies the drop-forging problemand makes a cheaper instrument, but the resharpening problem stillpersists. Such blades when mechanically secured to the shank, arecomparatively heavy, are ground to shape like any scissor blade, and aretoo costly to be dis-' 3 carded rather than resharpened. The weldedblade becomes, of course, an integral part of the shank, and thecompleted instrument therefore presents no advantages over scis .sorshaving blades of tool steel throughout.

The practical utility of inventions of this class requires that thescissors shanks and blades be of such design and construction as topermit of a low initial cost of production; .the cost of replacementblades to the user should be considerably lower than the expense ofgrinding; the blade should be read ily and securely attachable to. theshank and conveniently detachable therefrom, without .the use of toolsand by" persons unskilled in mechanical matters; and this attachment;

should be possible without taking, the shanks apart or removing theking-pin.

The cutting edges of scissors commonly define a helical or threedimensional curve,

the curvature depending upon the type of This is expensive andinscissors and the work for which they are designed. To grind this curveinto each blade would involve a prohibitive expense where the blade isto be discarded after the first'dulling, and I therefore make my bladestraight, but soflexible as to be conformable to any curve or twistnormally defined by the permanent shank on which the blade is mounted.position each shank is provided with a longitudinal beador undercut railextending along its operative edge and conforming to its curvature, andeach blade is provided with a corresponding longitudinal slotted recess.The blade can therefore be slid lengthwise over the bead, and because ofits universal flexibility, conforms perfectly to the curvature. Thissliding movement may be either inward from the tip toward the handle, oroutward from the handle toward the tip. If the former, then I haveprovided when necessary means for positively holding'the blade againstlongitudinal displacement, but if the latter the provision of a stop atthe tip is suflicient to prevent displacement becausethere is no endwardthrust and no tendency for the blade to creep toward the handle.

In my copending Patent No. 1,620,225 I have described scissors havingremovable blades rolled into position on the shanks by a transverserolling motion. Such scissors are satisfactoryfor many uses; I havediscovered, however, that when using them to cut heavy material there isa tendency for the shanks to spread permitting the blades to roll ortilt out of place. In the scissors of the present invention any suchlateral displacement of the blades is impossible.-

The blade of the present invention, in order that itmay possess theuniversal flexibility so important if it is to conform to the curvatureof the shank, is of small transverse dimensionsthus a blade for barber'sscissors of average size is about 5/64 of an inch high and about 1/32 ofan inch wide. Such a blade is indeed a specially shaped steel wire.

In the accompanying drawings 1 have illustrated a number of embodimentsof my in- To mount this blade in cutting vention, showing the manner inwhich the blade is mounted upon the shank.

In these drawings, Figure 1 is an elevation of a pair of scissorsequipped with removable blades in accordance with this invention; Figure2 is a similar view, on an enlarged scale, of a part of one of theshanks; Figure 3 is a transverse section on a still larger scale takenalong line 33 of Figure 2; Figure 4 is a perspective of a section of oneof the blades, on the scale of Figure 3; F igure'5 is a perspective, ona very much enlarged scale, of a portion of a shank showing the innerend of the bead and the means for locking the blade against longitudinaldisplacement; Figure 6 is a perspective, on the scale of Figure 5 of theinner end of a blade shaped to be mounted on the shank of F igure 5;Figure 7 is a perspective similar to Figure 1, but showing scissors onwhich the blades are intended to be slid onto the shanks from the innerend; Figure 8 is a perspective, on an enlarged scale of the outer or tipend of one of the shanks illustrated in Figure 7: Figure 9 is aperspective, on the scale of Figure '8, of the outer end of a bladeshaped to be mounted on the shank of Figure 8; Figure 10 is a transversesection, on an enlarged scale, taken along line 1010 of Figure 7; Figure11 is a transverse section on a very much enlarged scale taken alongline l111 of Figure 7; Figure 12 is a fragmentary elevation of a pair ofscissors similar to those of Figure 7, but showing means for guiding theforward end of the blade over the bead Figure 13 is a transverse sectionon' an enlarged scale taken along line 1313 of Figure 12; Figure 14 IS atransverse sectlon also on an enlarged scale taken along line- 1414 ofFigure 12, Figure 15 is a longitudinal section taken along line 1515 ofFigure 13; Figure 16 is a view similar to Figure 15 but illustrating amodified form of construction; Figure 17 is a view similar to Figure 12,but illustrating a modified fornr of guide means; Figure 18 is atransverse section, on an enlarged scale, taken along line 1818 ofFigure 17; Figure 19 is a view similar to Figure 18, but illustrates amodified form of construction; and Figure 20 is an enlarged section of amodified form of blade embodying the invention.

The scissors shown in Figure 1 comprise shanks 1, pivoted together bymeans of the ordinary kingpin 2. The shanks are formed to the compoundcurve common in scissors a convexity in the shear face between the kingpin and tip, illustrated in Figures 1 and 2, and a concavity in a plane90 to the shear face, not shown. Each of the shanks is provided on itsoperative edge with a longitudinal bead or undercut rail 3, extendingfrom the tip of the shank to a point adjacent that part defined by thecompanion shank when the scissors are in their wide-open position.

The form of this head or rail is such as to leave an enlarged portionconnected to the shank by a neck portion 4. Beyond the inner end of thebead, the inner face of the shank is formed with a depression 5 toreceive an extension on the blade as will be presently explained. Abevel-faced stud 6 extends outward from the bottom of the depression 5.

The blade 7 comprises a strip of drawn steel of roughly quadrant crosssectional outline. Formed; in this blade and extending longitudinallytherethrough is a recess 8, communicating with a slot 9 extending alongthe bottom ofthe blade, the recess and slot being shaped to embrace thehead 3 and neck 4 so as to prevent lifting or tilting of the blade. Theface 10 of the blade terminates in a cutting edge 11. At its inner endthe arcuate portion of the blade is cut away for a short distance at 12,as best illustrated in Figure 6, leaving a thin plate-like exten sion 13which is notched at 14 to engage the stud 6, thereby locking the bladeto the shank against longitudinal displacement.

The blade is attached to the shank in the following manner: The scissorsase opened, and the tip end of the bulbous portion of the bead or rail 3is inserted in the recess 8 of the blade element, which is so positionedwith reference to the shank that the cut-away part of the blade is onthe outer side of the shank. In this position, the neck 4 of the bead orrail enters the slot 9 of the blade, the sides of the slot exerting aslight spring pressure against the thereby embraced neck, thus taking upany possible slack and avoiding the necessity for accurate fitting. Thisspring tension may, in fact, hold the blade so firmly in place as toobviate the necessity for special locking means in some instances. Theblade is then pushed along the head or rail 3 until the extension 13enters the depression 5 and the notch 14 snaps into engagement with thestud 6.

The blade, either of the type illustrated in Figure 4 or in Figure 20embraces portions of the face and back of the shank and is thus heldagainst lateral displacement either by lifting or tilting.

Formed in each of the scissors shanks ad-' jacent stud 6 is an arcuateslot 15. When a blade has become dulled, pressure applied with thethumb-nail from the outer side of the shank through the slot 15 springsthe inner end of the blade out of engagement with stud 6, thuspermitting the blade to be pulled lengthwise along the head or railuntil dis-- engaged from the shank.

In the form of scissors illustrated in Figures 1, 2, 3, 4, 5 and 6 theblade is slid onto the head 3 from the tip inward. In Figures 7 to 19 Ihave shown howthe blade can be slid from the inner end of the beadoutward-toward the tip.

In the form shown in Figure 7 the head 3 is extended beyond the king-pinand terminates in an open end. At the tip the shank is provided with astop 16 which extends half way up the head, as shown most clearly inFigure 8, and the outer end of the blade is cut away along its lowerside at 17' to receive this stop. The blade is mounted on the shank byslipping it outward along the bead. The stop 16 prevents movement beyondthe end of the shank, but the cutaway 17 permits the cutting edge toextend to the very tip. No means are provided for holding the bladeagainst inward displacement because the normal thrust is outward.

In Figure 12 I have illustrated the scissors of Figure 7 equipped withguideways 18 alined with the beads 3 for facilitating the mounting ofthe blades. These guideways are preferably madequadrantal in crosssection as shown in Figure 13 The beadmay extend just up to the adjacentend of the guideway, as illustrated most clearly in Figure 15, or it mayenter the guideway as shown in Figure 16. In either case the outer endof the guideway is provided witha flaring bell mouth 19 for more readilyreceiving the blade.

In Figure 17 I have illustrated another form of guideway. Here the beadterminates 011 the near side of the king-pin and an alined guideway 20continues on a gentle curve back through the body of the shank openingat the other end on the inner side of the handle. This guideway iscircular in transverse section but may terminate in a bushing 21 shapedmore nearly to the configuration of the blade.

T he blades described above are made from the best tool steel, rolled,planished and tempered in a manner to be hereinafter described. They arevery flexible and will spring at'right angles to the cutting edge, orlongitudinally in any direction, either laterally or edgewise, through360, also helically, so that they are conformable to whatever curve theshank may have. Thus, the blades can be made in straight wire form,hardened, tempered and ground to a straight cutting edge while inlength, and cut oil to size, without specially grinding them to theshape and twist of the shank. No particular mechanical skill is requiredto easily and quickly place them in position upon their shanksnor areany tools necessary for effecting the attachment or detachment of theelements.

It will be evident from an examination of the drawings that the designand construction of the blade and shank-are such as to insure verysecure operative attachment therebetween. It will further be apparentthat the locking connect-ion between the elements, and the direction ofthe cutting thrust when the scissors are in use, are such as to minimizethe likelihood of lint, hair or other material becoming lodged in thejoints betweenthe blade and the shank. The bead or ,Whereas, withscissors of the conventional :4

material is progressively ground away ype; until'the scissors eventuallybecome useless,

the shank portions of the scissors made in accordance with thisinvention merely perform the function of supporting the blades, and willtherefore last indefinitely. Moreover, as these shanks do not require tobe made of hardened and tempered tool steel,

the initial cost of material and labor is p markedly reduced. The methodfor making the blade of the present invention is illustrated, describedand claimed in my Patent No. 1,814,182 issued July 1-i,193

I claim:

1. Scissors comprising the combination of a shank having a curvedoperative edge, and a blade normally straight flexible transversely inany slidabl-e longitudinally onto and off the shank and cooperatingmeans on said blade and shankfor preventing lifting or tilting of theblade.

2. Scissors comprising the combination of a shank having a curvedoperative edge, an undercut bead extending along said edge andconforming to its curvature, and a blade flexible transversely in anydirection having a longitudinal recess shaped to embrace the bead on theshank, whereby the blade may be mounted upon and removed from the shankby a longitudinal sliding movement and held against lateraldisplacement.

3. Scissors comprising the combination of a shank having a curvedoperative edge, an undercut bead extending along said edge andconforming to its curvature, and a blade flexible transversely in anydirection having a longitudinal recess shaped to embrace the bead on theshank, whereby lateral displacement is prevented and means for lockingthe blade against longitudinal displacement.

4. Scissors comprising the combination of a shank, a blade slidablelongitudinally outward toward the top of the shank. interldcking meanson the shank and the blade for mounting the latter upon the former, anda guideway at the inner end of the shank for guiding the blade intoposition on the shank.

5. Scissors comprising the combination of a shank having a curvedoperative edge, a bead extending along said edge and conforming to itscurvature, a blade flexible transversely in any direction having alongitudinal. recess shaped to embrace the bead on the shank, and a stopat the tip of the shank preventing outward longitudinal displace ment ofthe blade,'the inner end of the bead being unobstructed so that theblade can be direction mounted thereon and ide ios

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slid outward upon the shank and toward the f). Scissors comprising thecombination of a shank having a curved operative edge, a bead extendingalong said edge and conform ing to its curvature, a blade flexibletransversely in any direction having a longitudinal recess shaped toembrace the bead on the shank, a stop at the tip of the shank preventingoutward longitudinal displacement of the blade, the inner end of thebead being unobstructed so that the blade can be slid outward upon theshank and toward the tip, and a guideway at the inner end of the shankand alined with the bead for guiding the blade onto the head. 7

7. Scissors comprising the combination of a shank having a curvedoperative edge, a bead extending along said edge and conforming toitscurvature, a stop at the tip of the shank along the lower part of thebead, a blade flexible transversely in any direction having alongitudinal recess shaped to-embrace the bead and a cut-away portion atits outer end shaped to embrace the stop, thus permitting the cuttingedge to extend to the tip of the shank, the inner end oft-he bead beingunobstructed so that the blade can be slid outward upon the shank andtoward the tip.

8. Scissors comprising the combination of ashank having a curvedoperative edge and a detachable universally flexible blade mounted onsaid edge and held against lateral displacement by embracing portions ofthe face and back of the shank.

9. Scissors comprising the combination of a shank, an undercut beadextending along the operative edge of said shank and a blade flexibletransversely in any direction having a longitudinal recess shaped toembrace the bead on the shank, whereby lateral displacement of the bladeis prevented. Y

10. Scissors comprising the combination of a shank and a bladelongitudinally mountable thereon and flexible transversely in anydirection to conform thereto and cooperating meanson the blade and shankfor preventing lifting or tilting of he blade.

11. Scissors comprising the combination of a shank, a blade mountedthereon flexible transversely in any direction to conform thereto andslidable longitudinally onto and off the shank, and means for positivelyholding the blade in contact with the shank throughout substantially theentire length of the blade and preventing lateral displacement of theblade in any direction.

12. Scissors comprising the combination of a shank, and a blade flexibletransversely in any direction to conform to the shank and mountedthereon by a longitudinal sliding interlock preventing lateraldisplacement of the blade and held positively in place by means of aspring tension.

13. Scissors comprising the combination of a shank having a curvedoperative edge, an undercut bead extending along said edge andconforming to its curvature and a spring steel bladeflexibletransversely in any direction. having a longitudinal recess shaped toembrace the head on the shank with a spring tension, whereby the blademay be mounted upon and removed from the shank by a longitudinal slidingmovement, maintained positively in position on the shank and heldagainst lateral displacement.

l4. Scissors comprising the combination of a shank, a blade flexibletransversely in any direction mounted on said preventing lateraldisplacementof the blade in any direction. v

15. Scissors comprising the combination of a shank, a blade flexibletransversely in any direction mounted on said shank and cooperatingmeans on said blade and shank for preven ing lifting and tilting of theblade relative to the shank.

16. Scissors comprising the combination of a shank, a blade flexibletransversely in any direction mounted on said shank, and cooperatingmeans on said blade and shank for preventing lateral displacement of theblade, said means comprising a longitudinally extending undercut bead onone of said members and a recess on the other shaped to embrace thebead.

17. A detachable blade for scissors transversely flexible in anydirection to conform to any conformation of the scissors shank andprovided with means cooperating with the shank for preventing lifting ortilting of the blade.

18. A detachable blade for scissors, made of spring steel, transverselyflexible in any direction to conform to any conformation of the scissorsshank and provided with a longitudinal recess shaped to embrace a beadon the shank with a spring tension and hold the blade against lateraldisplacement.

In testimony whereof I afiix my signature.

MORGAN PARKER,

shank and cooperating meanson said blade and snank for

